john banks

Maybe it has not been tested in these freezing conditions Dave?

I fail to understand how something that reduces exhaust back pressure cannot affect boost control using the method Subaru use with a max-min duty cycle, boost target and ramp rate depending on boost error. It is like having your cake and eating it. I would suggest in the absence of evidence otherwise (especially with the VF3x restricted wastegate cap at high RPM) that STi 7s with decats/free flowing exhausts should have their boost setup by restrictor adjustment at the least, or at least for all installers to be aware of the issue and check?

Also, because of the restricted wastegate capacity, the closed loop control system doesn't work properly at high revs, so a large part of the power gain from exhausts is probably the extra boost... a little bit like induction kits leading to MAF under-reads (making it leaner and more advanced, so more torque/power up to a point) - probably a fair bit of the gain (and loss in torque) is due to this rather than breathing improvements? Just a thought...

[Edited by john banks - 12/19/2002 12:24:04 PM]

Razor2001

Thanks Dave T-S, that makes me a little more comfortable knowing that my max peak is 1.3 and 100% bog standard UK-STi-7's peak at 1.4 at times...thanks for that

John, on your last post I think I read that after a zorst install you will have less torque ? Did I read that correctly ?

For example with my JDM STi-7 you are saying that with a full turbo back decat and restrictor fix (as stated earlier max spike on delta dash and boost guage is 1.3 no matter what test used) that I may have gained 15 - 30 bhp but I have lost torque ? Surely the torque should come in earlier on a graph with the breathing freed up ? thoughts please

Cheers,
Ray

Pete Croney

Ray

I think what John was saying is that you will have more torque if you leave the standard restrictor in place, but you also risk dangerous boost spikes, especially during a cold British winter.

Rob is lucky that he has a Knocklink and has seen he has a serious problem. Many will not see this until its too late, all for the sake of a £5 restrictor.

Its almost impossible to hear det over the road noise, over about 50-60mph, unless wearing det cans.

Razor2001

Cheers Pete

john banks

I really meant torque loss from being lean with an induction kit. I am asserting that the gains from induction kits and exhausts are not entirely due to good breathing, but from overboost and MAF misreads. Sometimes they go too far = det, other times surprisingly good results.

Rob D

Dave,

Thats what I was led to believe, I was reading around 1.5 bar (see note below) with the Milltek setup, which was the same as my previous Scoobysport setup (2 mids and BB) on a Defi boost gauge.
I think John has hit the nail on the head in regards of the cold weather and the effects it is having, the boost is really still the same.
I always have run my car on SUL or Optimax, and like Pete says I knew immediately from the readings on the Knocklink what was happening.
Anyone have a KL with a PPP?

Cheers,

Rob.

P.S Forgot to add my Deltadash readings are only seeing 18.4 psi peak boost, that brings it around 1.3 bar and not 1.5 bar so not sure if the Defi gauge can read spikes that well.
John can you comment on this or anyone that can explain the difference between DD and my gauge?

[Edited by Rob D - 12/19/2002 5:19:17 PM]

Razor2001

bttt for an answer to Rob's 'PS' above

nom

I'm going to have a bash at the gauges thing - apologies in advance!
DD has a sample rate - it doesn't record absolutely every point, just a lot. The peak may be too fast for it to pick up. The gauge will pick up a peak - but may not show it. I don't know the Defi's - they 'record', don't they? But I don't know how the display... The SPAs that I have display & record: on a run, DD would show 16.6psi, the gauge would display 16.6psi, but the peak (when clicking the 'display peak' button ) could be around 17.5psi - it just happened so fast the gauge picks it up but is too damped to display it, the ECU picked it up & acted on it, but DD's sampling/view wasn't 'fast' enough (not enough points) to show it.
I'm over explaining again. I'll go away now

john banks

Select monitor protocol saturates at 18.4 PSI so you see a clipped result. Ecutek tuners have a DD version which displays v1/2/3 unscaled MAP in absolute bar and goes up to whatever you MAP sensor will - on MY99/00 that is about 1.8 bar (2.8 bar absolute). AFAIK, the unscaled MAP thing is not available for MY01/STi 7. You might want to email Ecutek and see if they can implement something in DD to read more than 18.4 PSI. With STis this is not enough to set them up properly.

DD sees most peaks since even on a lame laptop it has a reasonable sample rate.

[Edited by john banks - 12/19/2002 8:04:44 PM]

Razor2001

So the most psi you will ever see on a DD for a STi-7 is 18.4 psi no matter if it hits 25 psi or whatever ?

Cheers,
Ray

john banks

Yep.

JIM THEO

John I've benn suggested to download latest DD version that has also "Absolute Manifold Pressure" column but if I am right this is only for >MY01 users right?
JIM

mutant_matt

Jim,

I think you're right but wait for John to confirm. John, are you saying that using the Absolute will not clip @ 33.1 Ab/18.4 Rel and will read up to 43psi Absolute? Or do you Ecutek tuner guys get the full reading, regardless of Relative or Absolute?

Ta,

Matt

john banks

I only get fuel reading with v1/2/3 unscaled map and it is in bar. Manifold relative pressure clips at 18.4. Not logged enough bugeyes to see if manifold absolute pressure is affected in the same way, but I can't find a manifold absolute pressure for MY99/00 in Delta Dash hence the internal variable v1/2/3 unscaled map as I mentioned. From the beginning this has been the only way to see full boost on my car since it has always had exciting boost levels

mutant_matt

OK,

Who's got an STi 7 regularly boosting to 19psi and has DeltaDash then?

Matt

Markus

overboost and hitting fuel cut, yummy! NOT!

Just have to keep my foot away from the floor and I'm ok

ScoobyJawa

I thought you'd sorted that mate? It was doing that at AT or is it just the cold weather making it worse again?

Could be worse, you could've had your turbo hitting 1.6 bar and knackering the wastegate lol!!

Markus

Neil,
umm, kinda nearly got it sorted. Got an adaptor board from www.scoobyecu.co.uk and got Scott.T to program the chips for me. Can now hold boost at 1.1bar, but still get fuel cut if I floor the little darling, Scott is programing up some more chips for me to try. But hey, it's quicker than before!

Razor2001

OK, any STi-7 owners out there with DeltaDash that have found a way to read over 18.4 psi ?

Cheers,
Ray

Worried now as I only have me old boost guage to see if I am spiking and if that is off then uh oh !

Razor2001

anyone ??

ScoobyJawa

Getting there then Nice one! Lets see what she's putting out at the RR day!

Deep Singh

Hi John(Banks).Had my car(JDM stI7 with full decat) delta dashed.I'm interested in the AFR readings.They were very rich ie 8.5,these have been changed to about 9.5 with Ecutek.Car runs much better know and really feels frisky! I'm wondering if all is well could some more fuel be trimmed off safely? There is no det shown on the delta dash logs or on my Knocklink,however I could still get a piston melt from very high cylinder temps,so how do you decide how far to go with leaning it out?
ps interesting point is that the ECU was advancing ignition of its own accord by up to 15 degrees!!
Many thanks for answering so many questions from all us Scoobynetters>

wacky.banana

Just come back to this thread. Seems we know very little as yet as to what is safe for the STi7, in terms of, say, engine & exhaust modding relative to, say, the older cars. Worries me greatly.

The more I read this board the more I know I am absolutely right to be mega cautious before jumping into anything. The fact that I cannot get the questions I am asking answered satisfactorily speaks volumes for me.

Hope this situ changes in 2003 so that STi7 owners can move to modifications which have been properly R&D'd, and are safe!

WB

Deep Singh

Wacky,yes its frustrating but also perversley exciting.Being 'involved' whilst things are being sorted makes one feel more a part of the whole situation rather than just a 'customer'

SCOSaltire

no overboost for me
my99 PPP decat
car has been going well... just been driving n having fun



[Edited by SCOSaltire - 12/22/2002 8:50:59 PM]

john banks

I run my Phase II at 11.4:1 AFR, but as Pat says in your other thread the STi is unknown so caution advised.